The experiments followed the increase of nitrogen from a source inorganic (urea) used in feeding cows and its effect on milk production and milk quality. The OPTIGEN product is used in proportions between 1 and 3% of fodder for cows in lactation, which means quantities of urea between 60 and 180 g/head/day , the inorganic total crude protein weight source intake of cows varied between 10 and 20%. The quantitative determination of milk production and its qualitative analysis have revealed very little differences both between batches and between determinations from the same batch, which after processing the statistical differences proved insignificant. These results demonstrate that inorganic nitrogen in the OPTIGEN product can be harnessed properly by the lactating cows, also causing nutrition specialists to find solutions allowing both increasing the weight ratio of the inorganic source, and improving the milk production and quality parameters.